A truck was running with hoses leading from the exhaust into a car in the family's Toledo garage Monday. Inside the vehicle were the bodies of 54-year-old Sandy Ford; her 32-year-old son, Andy Ford; and her grandchildren, 10-year-old Paige Hayes, 6-year-old Logan Hayes and 5-year-old Madalyn Hayes, police said.

Sandy Ford's husband, Randy, called police Monday afternoon to say that he had returned home and found suspicious notes in the house from his wife, son and grandkids. He said he wasn't able to enter the garage.

Firefighters used a sledgehammer to open a door to the garage, which had been barricaded shut. The bodies of the five people, two dogs and one cat were found inside the car.

Investigators believe they died of carbon monoxide poisoning. The five victims lived with Randy Ford in the house, located in a residential neighborhood close to the Michigan state line.